Soluble azo dyes



All)

' prepared from them are distinguished by Patented Jan. 6,

' TUNE?- ST 'F inan JoHANN nnrsivrnnn an]; nneolscnwn'rrznn, on wrnsnonr-o'n-rnn-nnrnn, AND, RICHARD s rnssnn or conoenn-pnnrz, GERMANY, AssIenons- TO GENERAL ANILINE won ts, .rno.,-or nnwyonn, N. Y., A'CORPGRATION on nnnnwnnn soiinB n AZO DYES No Drawing. Application filed January l9 ,1$i28,Seria1 No. 248,805, ant1 in Germany January 19,1927.

The present invention concerns new and valuable azo dyestuffs of the generalformula R=N= N=(bn to N-HRi wherein Rmepresents an aromatic nucleus which is substitutedby a nitro group in ortho position to the azo group and which may be further substituted by any substit-uent with the exception of a sulfo group and R represents an aromatic nucleus which is sub-' stitutedby a sulfo group and which may be further substituted. i

. Our new dyestuffs can be prepared, for instance, by coupling a diazotized ortho-nitro arylamine with an aceto-acetarylide and treating the azo dyestuff thus obtained with a sulfonating agent in the usual manner, e. g. suliuricacid monohydrate orchlorosuffonic acid in an inorganic or organic solvent such as sulfuric acid monohydra te or chlorobenzene, thus converting the same into derivatives which are sultfonated in the aryl nucleus of the coupling components or alternatively by coupling a diazotized arylamine with auaceto-acetarylide compound which is substituted in the aryl residue by asuli'onic acid group.

Our new dyestuffs, after being dried and pulverized, are generally in the form of their alkali metal salt yellow to orange powders soluble in water and sulfuric acid with a yellow coloration, difficulty soluble, or in soluble in organic solvents. The color lakes full yellow shades, clearness and fastnessto light. The new products dyeWvool' evenly clear yellow shades of superior fastness to light and fulling. i

The following examples will illustrate our invention without. li 'ting itthereto.

Example 1.-3'.

hpart's. by weight of the dyestnil B-nitro-I-rnethj, l-benzene-l-a.Zo'-ace to-acet-ortho-chloroanilide are introduced gradually at about 10 Cfinto 7500 parts by ring is efi'ected forseveral hours, the temperature gradually rising to about C. lVhcn thesulfonationis complete the ma? is poured on to ioeand ,water', the precipitated dyestuff:

' is filteredoff, rendered alkalinewith sodium carbonate and dissolved. in hot water. It is agains precipitated. from the hot solution I with asmall amount of common salt filtered dried andfi'orms alight yellow powder, In its free state it has most probably the following formula SOsH When used as a size color it gives a greenishevenly.

I t V Ermmpic 2.57O parts by weight of the dyestufi 3 nit-ro-l-inethyl-benzene--azo-aceto-acet ortho-'anisidide are dissolved in about 10 times theweightof chlorobenzene while slowly heating." The solution is cooled down to about iO- C, and 140 parts by weight of chlorosul lfonic acid are caused 'to' drop in slowly while stirring well. The sulfonation commences soon with vigorous evolution of hydrogen-chloride. In order to complete the reaction heating is finally resorted to for some time to about 90 (1., when the completely sulfonated mass is poured into water. The reaction nu ture is rendered alkaline with a small excess of sodium carbonate and the chlorobenzene is removed by'means of steam, passed through the solution. The dyestuif can then be saltedout from the still hot fil-1 tered solutionfby the addition lot common ion formula y 1 which may be further'substituted and R represents an aromatic nucleus which is substituted by a sulfo group andwhich may be further substituted; beingnin the form ofthe alkali metal salts yellow to orange powders, ex-

hibiting various yellow shades of outstanding clearness and fastnessto light and water as size colors and dyeing wool clear yellow shades ofsuperior fastness' to: light and l SOaH H1611 dried itforms a yellow powder, which.

dissolves with ease in hot water, it can be easily precipitated to produce a clearyellow lake which is fast to light and water when used'as a size color. 'It dyes wool evenly with clear, reddish-yellowshades; which; are fast to light and fulling. V Ema-ample 3.172.5 parts by weight of 4- chloro-Q-nitro-aniline are mixed with water to form a paste anddiazotized with 69 parts by weight of sodium nitrite in the usual manner in the presence of about 360'parts by weight of hydrochloric acid (19.5 B.) The filtered solution of the diazo compound is poured slowly into a cold aqueous solution of 278 parts by weight of the sodium salt of aceto-acet-2-anisidide 4 sulfonic acid A to p which has been added an aqueous solution of 500 parts by weight of, crystallized sodium acetate. rendered soda alkaline and "the dyestuff is salted out. In its free state it has probably the formula to V I V V es SOaH wherein R represents an unsulfonated aro After some hours the solution is monoazo dyestuif having fulling.

2. As new products water soluble monoazo dyestuffs having most probably-the formula:

wherein R representsan unsulfonated benzene nucleus which is'substituted by a nitro group in ortho-position to the azo group and which may} be further substituted and R represents a'benzene nucleus which'is substituted in paraposition to the 'NH-group by a su'lfonic acid group and whichmay be'further substituted, said compounds being in the'formofthe alkali metal salts yellow to oran e powders exhibiting various yellow shades of outstanding clearne'ss and' fastness to light and water as size colorsand dyeing i to light and fulling. 1

3. As a new. product the water soluble in its free state most probably the formula a wool clear yellow shades of superior fastness OaH being inform of its sodium salt a light yellow powder exhibiting as a size color a yellow shade of outstanding clearnes's and fastiiess to light and water and dyeing wool clear yellow shades of fulling.

In'testimony whereof we have hereunto set our hands, V

' JOHANN HUISMANN,

HUGO SQHWEITZER RICHARD TSTUSSER.

good fastness to light and 

